chore(deps): update actions/cache action to v2.1.8

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
actions/cache	action	patch	v2.1.7 -> v2.1.8

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Release Notes

actions/cache (actions/cache)

### [`v2.1.8`](https://togithub.com/actions/cache/releases/tag/v2.1.8): Updating actions/core to version 1.10.0 [Compare Source](https://togithub.com/actions/cache/compare/v2.1.7...v2.1.8) The ::save-state and ::set-output are deprecated. The newer version of actions/core >1.10.0 uses the new syntax for save and set output. After this change, customers using actions/cache@v2 won't see deprecation warning message.

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Configuration

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[sonarcloud[bot]]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
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[codecov[bot]]

Codecov Report

Merging #89 (7113487) into master (fdce630) will not change coverage. The diff coverage is n/a.

@@            Coverage Diff            @@
##             master      #89   +/-   ##
=========================================
  Coverage     97.77%   97.77%           
  Complexity      147      147           
=========================================
  Files             1        1           
  Lines           404      404           
=========================================
  Hits            395      395           
  Misses            9        9           

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